Photoresist comprising nitrogen-containing compound

ABSTRACT

New nitrogen-containing compounds are provided that comprise multiple hydroxyl moieties and photoresist compositions that comprise such nitrogen-containing compounds. Preferred nitrogen-containing compounds comprise 1) multiple hydroxyl substituents (i.e. 2 or more) and 2) one or more photoacid-labile groups.

This invention relates to new nitrogen-containing compounds thatcomprise multiple hydroxyl moieties and photoresist compositions thatcomprise such nitrogen-containing compounds. Preferrednitrogen-containing compounds comprise 1) multiple hydroxyl substituents(i.e. 2 or more) and 2) one or more photoacid-labile groups.

Photoresists are photosensitive films for transfer of images to asubstrate. They form negative or positive images. After coating aphotoresist on a substrate, the coating is exposed through a patternedphotomask to a source of activating energy such as ultraviolet light toform a latent image in the photoresist coating. The photomask has areasopaque and transparent to activating radiation that define an imagedesired to be transferred to the underlying substrate.

Known photoresists can provide features having resolution and sizesufficient for many existing commercial applications. However for manyother applications, the need exists for new photoresists that canprovide highly resolved images of submicron dimension.

Various attempts have been made to alter the make-up of photoresistcompositions to improve performance of functional properties. Amongother things, a variety of basic compounds have been reported for use inphotoresist compositions. See, e.g., U.S. Pat. Nos. 6,607,870 and7,379,548.

In one aspect, we now provide novel nitrogen-containing compounds foruse in both positive-acting and negative-acting photoresistcompositions. Photoresists of the invention suitably may comprise one ormore resins (resin component) and one or more one or more photoacidgenerator compounds (photoacid generator or PAG component) in additionto one or more nitrogen-containing compounds (nitrogen-containingcomponent).

Preferred nitrogen-containing compounds of the invention for use inphotoresists may comprise 1) two or more hydroxyl substituents and 2)one or more photoacid-labile groups. Typical photoacid-labile groupsundergo bond-breaking in the presence of exposure-generated acid in aphotoresist layer, during lithographic processing of the photoresist(including e.g. during post-exposure baking of the photoresist layer).

We have surprisingly found that use of nitrogen-containing compounds asdisclosed herein in a photoresist composition, includingchemically-amplified photoresist compositions, can significantly enhanceresolution of a relief image (e.g. fine lines) of the resist. Inparticular, we have found that including a second (or more than 2)hydroxyl groups on an nitrogen-containing compound can impartsignificantly enhanced lithographic results, including relative to acomparable photoresist that is otherwise identical to the photoresistcontaining a multi-hydroxy nitrogen-containing compound of theinvention, but where in the comparative photoresist thenitrogen-containing compound has only a single hydroxyl moiety. See, forinstance, the comparative data set forth in Examples 5 and 6, whichfollow.

Without being bound by theory, nitrogen-containing compounds asdisclosed herein can function as quencher elements in a photoresist andrestrict migration (diffusion) of photogenerated acid (in the case of apositive-acting resist) out of exposed regions and into unexposedregions which migration could compromise resolution of the imagepatterned into the resist layer.

Preferred nitrogen-containing compounds of the invention for use inphotoresists may be polymeric or non-polymeric, with non-polymericmaterials preferred for many applications. Preferred nitrogen-containingcompounds have relatively low molecular weight, e.g. a molecular weightof less than 3000, or even less such as a molecular weight of less than2500, 2000, 1500, 1000, 800 or 500.

Particularly preferred nitrogen-containing compounds of the inventionfor use in photoresists include nitrogen-containing compoundsrepresented by the following Formula (I):

wherein R¹ and R² are the same or different and at least one of R¹ andR² is other than hydrogen, and together R¹ and R² comprise at least twohydroxyl groups (i.e. R¹ may comprise at least two hydroxyl groups; R²may comprise at least two hydroxyl groups; or R¹ may comprise at leastone hydroxyl group and R² may comprise at least one hydroxyl group), orR¹ and R² may be taken together to form a ring where the R¹/R² ring(including substituents thereof) comprises at least 2 hydroxy groups;and

X comprises a photoacid-labile group, such as a photoacid-labile esteror acetal group.

Preferred R¹ and R² groups include hydrogen and optionally substitutedalkyl, carbocyclic aryl (e.g. phenyl, naphthyl), and the like where themoieties include hydroxyl substitution (e.g. hydroxyalkyl having 1 to 20carbon atoms). If R¹ and R² are taken together to form a cyclicstructure with the nitrogen, where the cyclic structure comprises two ormore hydroxyl groups.

In certain preferred embodiments, R¹ or R² is hydrogen, and thenon-hydrogen group comprises at least two hydroxyl groups, such asnitrogen-containing compounds of the following Formula (IIA).

wherein in Formula (IIA) R^(1′) is a non-hydrogen substituent thatcontains at least 2 hydroxy groups such as C₁₋₂₅alkyl that has two ormore hydroxyl group ad the like; and X is the same as defined forFormula (I) above i.e. a photoacid-labile group, such as aphotoacid-labile ester or acetal group.

In additional preferred embodiments, preferred nitrogen-containingcompounds comprise a photoacid-labile ester group, such as compounds ofthe following Formula (IIB).

wherein in Formula (IIB) R¹ and R² are the same as defined as defined inFormula (I); and R₁, R₂ and R₃ each independently represent anoptionally substituted straight, branched or cyclic group of 1 to 30carbon atoms.

Additional preferred nitrogen-containing compounds include those of thefollowing Formula (IIC):

wherein R₁, R₂ and R₃ each independently represent an optionallysubstituted straight, branched or cyclic group of 1 to 30 carbon; R₄represents hydrogen or a straight, branched or cyclic group of 1 to 30carbon; m1, m2 and m3 are each independently an integer of 0 to 30; n1,n2 and n3 are each independently an integer of 0 or 1; at least twoamong n1, n2 and n3 are 1.

Still additional preferred nitrogen-containing compounds include thoseof the following Formula (IID):

wherein R₁, R₂ and R₃ each independently represent a straight, branchedor cyclic group of 1 to 30 carbon; R₄ represents hydrogen or anoptionally substituted straight, branched or, cyclic group of 1 to 30carbon; n is an integer of 1 to 30; and n is a positive integer e.g.from 1 to 20.

Exemplary specifically preferred nitrogen-containing compounds for usein photoresists include the following structures A, B, C, D, E and F. Asshould be understood, in the below structures as well as elsewhereherein, the designation “t-BOC” refers to the moiety-(C═O)OC(CH₃)₃.

Preferably, nitrogen-containing compounds of the invention are used inpositive-acting or negative-acting chemically amplified photoresists,i.e. negative-acting resist compositions which undergo aphotoacid-promoted crosslinking reaction to render exposed regions of acoating layer of the resist less developer soluble than unexposedregions, and positive-acting resist compositions which undergo aphotoacid-promoted deprotection reaction of acid labile groups of one ormore composition components to render exposed regions of a coating layerof the resist more soluble in an aqueous developer than unexposedregions. Ester groups that contain a tertiary non-cyclic alkyl carbon ora tertiary alicyclic carbon covalently linked to the carboxyl oxygen ofthe ester are generally preferred photoacid-labile groups of resinsemployed in photoresists of the invention. Acetal groups also aresuitable photoacid-labile groups.

Preferred imaging wavelengths of photoresists of the invention includesub-300 nm wavelengths e.g. 248 nm, and sub-200 nm wavelengths e.g. 193nm and EUV.

Particularly preferred photoresists of the invention contain animaging-effective amount of one or more PAGs and a nitrogen-containingcomponent as disclosed herein and a resin that is selected from thegroup of:

1) a phenolic resin that contains acid-labile groups that can provide achemically amplified positive resist particularly suitable for imagingat 248 nm. Particularly preferred resins of this class include: i)polymers that contain polymerized units of a vinyl phenol and an alkylacrylate, where the polymerized alkyl acrylate units can undergo adeblocking reaction in the presence of photoacid. Exemplary alkylacrylates that can undergo a photoacid-induced deblocking reactioninclude e.g. t-butyl acrylate, t-butyl methacrylate, methyladamantylacrylate, methyl adamantyl methacrylate, and other non-cyclic alkyl andalicyclic acrylates that can undergo a photoacid-induced reaction, suchas polymers in U.S. Pat. Nos. 6,042,997 and 5,492,793, incorporatedherein by reference; ii) polymers that contain polymerized units of avinyl phenol, an optionally substituted vinyl phenyl (e.g. styrene) thatdoes not contain a hydroxy or carboxy ring substituent, and an alkylacrylate such as those deblocking groups described with polymers i)above, such as polymers described in U.S. Pat. No. 6,042,997,incorporated herein by reference; and iii) polymers that contain repeatunits that comprise an acetal or ketal moiety that will react withphotoacid, and optionally aromatic repeat units such as phenyl orphenolic groups.

2) a resin that is substantially or completely free of phenyl groupsthat can provide a chemically amplified positive resist particularlysuitable for imaging at sub-200 nm wavelengths such as 193 nm.Particularly preferred resins of this class include: i) polymers thatcontain polymerized units of a non-aromatic cyclic olefin (endocyclicdouble bond) such as an optionally substituted norbornene, such aspolymers described in U.S. Pat. No. 5,843,624 incorporated herein byreference; ii) polymers that contain alkyl acrylate units such as e.g.t-butyl acrylate, t-butyl methacrylate, methyladamantyl acrylate, methyladamantyl methacrylate, and other non-cyclic alkyl and alicyclicacrylates; such polymers have been described in U.S. Pat. No. 6,057,083.Polymers of this type may contain in preferred aspects certain aromaticgroups such as hydroxynaphthyl.

Resists of the invention also may comprise a mixture of distinct PAGs,typically a mixture of 2 or 3 different PAGs, more typically a mixturethat consists of a total of 2 distinct PAGs.

The invention also provide methods for forming relief images of thephotoresists of the invention, including methods for forming highlyresolved patterned photoresist images (e.g. a patterned line havingessentially vertical sidewalls) of sub-quarter micron dimensions orless, such as sub-0.2 or sub-0.1 micron dimensions.

The invention further provides articles of manufacture comprisingsubstrates such as a microelectronic wafer or a flat panel displaysubstrate having coated thereon the photoresists and relief images ofthe invention. Other aspects of the invention are disclosed infra.

FIGS. 1A and 1B are SEMs that depict results of Example 5 which follows.

FIGS. 2A and 2B are SEMs that depict results of Example 6 which follows.

Photoresists of the invention may comprise one or more hydroxylnitrogen-containing compounds in a wide amount range. The added hydroxynitrogen-containing component is suitably used in relatively smallamounts, e.g. about 0.5 to 10 or 15 percent by weight relative to thePAG, more typically 1 to about 5, 6, 7, 8, 9 or 10 weight percent.

Nitrogen-containing compounds as disclosed herein can be readilysynthesized. For instance, a nitrogen-containing polyol compounds can bereacted to provide a pendant photoacid-labile ester or acetal group.See, for instance, the syntheses of Examples 1 and 2, which follow. Manyreagents to form desired nitrogen-containing compounds are commerciallyavailable.

As stated herein, various substituent groups of nitrogen-containingcompounds of the invention may be optionally substituted. Substitutedmoieties are suitably substituted at one or more available positions by,e.g., halogen such as F, Cl Br and/or I, nitro, cyano, sulfono, alkylincluding C₁₋₁₆ alkyl with C₁₋₈ alkyl being preferred, haloalkyl such asfluoroalkyl (e.g. trifluoromethyl) and perhaloalkyl such asperfluoroC₁₋₄alkyl, alkoxy including C₁₋₁₆ alkoxy having one or moreoxygen linkages with C₁₋₈ alkoxy being preferred, alkenyl includingC₂₋₁₂ alkenyl with C₂₋₈ alkenyl being preferred, alkenyl including C₂₋₁₂alkenyl with C₂₋₈ alkynyl being preferred, aryl such as phenyl ornaphthyl and substituted aryl such as halo, alkoxy, alkenyl, alkynyland/or alkyl substituted aryl, preferably having the number of carbonatoms mentioned above for corresponding groups. Preferred substitutedaryl groups include substituted phenyl, anthracenyl and naphthyl.

As used herein, the term alkyl, alkenyl and alkynyl unless otherwisemodified refers to both cyclic and noncyclic groups, although of coursecyclic groups will comprise at least three carbon ring members. Alkenyland alkynyl groups of compounds of the invention have one or moreunsaturated linkages, typically 1 to about 3 or 4 unsaturated linkages.Also, the terms alkenyl and alkynyl as used herein refer to both cyclicand noncyclic groups, although straight or branched noncyclic groups aregenerally more preferred. Alkoxy groups of PAG compounds of theinvention have one or more oxygen linkages, typically 1 to about 5 or 6oxygen linkages. Alkylthio groups of PAGs of the invention have one ormore thioether linkages, typically 1 to about 5 or 6 thioether linkages.Alkylsulfinyl groups of PAG compounds of the invention have one or moresulfinyl (SO) linkages, typically 1 to about 5 or 6 sulfinyl linkages.Alkylsulfonyl groups of PAG compounds of the invention have one or moresulfonyl (SO₂) linkages, typically 1 to about 5 or 6 sulfonyl linkages.Preferred alkylamino groups of PAG compounds of the invention includethose groups having one or more primary, secondary and/or tertiary aminegroups, preferably 1 to about 3 or 4 amine groups. Suitable alkanoylgroups have one or more carbonyl groups, typically 1 to about 4 or 5carbonyl groups. Alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl,alkanoyl and other groups may be suitably either linear or branched.Carbocyclic aryl as used herein refers to non-hetero aromatic groupsthat have 1 to 3 separate or fused rings and 6 to about 18 carbon ringmembers and may include e.g. phenyl, naphthyl, biphenyl, acenaphthyl,phenanthracyl, and the like. Phenyl and naphthyl are often preferred.Suitable heteroaromatic or heteroaryl groups will have 1 to 3 rings, 3to 8 ring members in each ring and from 1 to about 3 hetero atoms (N, Oor S). Specifically suitable heteroaromatic or heteroaryl groups includee.g. coumarinyl, quinolinyl, pyridyl, pyrazinyl, pyrimidinyl, furyl,pyrrolyl, thienyl, thiazolyl, oxazolyl,

As discussed, photoresists of the invention typically comprise a resinbinder and a photoactive component of the invention as described above.Preferably the resin binder has functional groups that impart alkalineaqueous developability to the resist composition. For example, preferredare resin binders that comprise polar functional groups such as hydroxylor carboxylate. Preferably the resin binder is used in a resistcomposition in an amount sufficient to render the resist developablewith an aqueous alkaline solution.

Preferably, a photoacid generator compound of the invention is employedin a chemically amplified positive-acting resist. A number of suchresist compositions have been described, e.g., in U.S. Pat. Nos.4,968,581; 4,883,740; 4,810,613 and 4,491,628 and Canadian PatentApplication 2,001,384, all of which are incorporated herein by referencefor their teaching of making and using chemically amplifiedpositive-acting resists. In accordance with the present invention, thoseprior resist compositions are modified by substitution of thephotoactive component of the invention as the radiation sensitivecomponent.

PAGs of the invention also are preferably used with polymers thatcontain one or more photoacid-labile groups and that are substantially,essentially or completely free of phenyl groups. Such photoresistcompositions are particularly useful for imaging with sub-200 nmradiation such as 193 nm radiation. As mentioned above, such resins ofthis type may in preferred aspects comprise certain aromatic groups suchas hydroxy naphthyl.

For example, preferred polymers contain less than about 5 mole percentaromatic groups, more preferably less than about 1 or 2 mole percentaromatic groups, more preferably less than about 0.1, 0.02, 0.04 and0.08 mole percent aromatic groups and still more preferably less thanabout 0.01 mole percent aromatic groups. Particularly preferred polymersare completely free of aromatic groups. Aromatic groups can be highlyabsorbing of sub-200 nm radiation and thus are undesirable for polymersused in photoresists imaged with such short wavelength radiation.

Suitable polymers that are substantially or completely free of aromaticgroups and may be formulated with a PAG of the invention to provide aphotoresist for sub-200 nm imaging are disclosed in European applicationEP930542A1 of the Shipley Company.

Suitable polymers that are substantially or completely free of aromaticgroups suitably contain acrylate units such as photoacid-labile acrylateunits as may be provided by polymerization of methyladamanatylacrylate,methyladamanylmethacrylate, ethylfencylacrylate,ethylfencylmethacrylate, and the like; fused non-aromatic alicyclicgroups such as may be provided by polymerization of a norbornenecompound or other alicyclic compound having an endocyclic carbon-carbondouble bond; an anhydride such as may be provided by polymerization ofmaleic anhydride; and the like.

Preferred negative-acting compositions of the invention comprise amixture of materials that will cure, crosslink or harden upon exposureto acid, and a photoactive component of the invention.

Particularly preferred negative acting compositions comprise a resinbinder such as a phenolic resin, a crosslinker component and aphotoactive component of the invention. Such compositions and the usethereof has been disclosed in European Patent Applications 0164248 and02329.72 and in U.S. Pat. No. 5,128,232 to Thackeray et al. Preferredphenolic resins for use as the resin binder component include novolaksand poly(vinylphenol)s such as those discussed above. Preferredcrosslinkers include amine-based materials, including melamine,glycolurils, benzoguanamine-based materials and urea-based materials.Melamine-formaldehyde resins are generally most preferred. Suchcrosslinkers are commercially available, e.g. the melamine resins soldby American Cyanamid under the trade names Cymel 300, 301 and 303.Glycoluril resins are sold by American Cyanamid under trade names Cymel1170, 1171, 1172, urea-based resins are sold under the trade names ofBeetle 60, 65 and 80, and benzoguanamine resins are sold under the tradenames Cymel 1123 and 1125.

As discussed above, photoresists for use in the invention also comprisea photoacid generator (i.e. “PAG”) that is suitably employed in anamount sufficient to generate a latent image in a coating layer of theresist upon exposure to activating radiation. Preferred PAGs for imagingat 193 nm and 248 nm imaging include imidosulfonates such as compoundsof the following formula:

wherein R is camphor, adamantane, alkyl (e.g. C₁₋₁₂ alkyl) andfluoroalkyl such as fluoro(C₁₋₁₈alkyl) e.g. RCF₂— where R is optionallysubstituted adamantyl.

Also preferred is a triphenyl sulfonium PAG, complexed with anions suchas the sulfonate anions mentioned above, particularly a perfluoroalkylsulfonate such as perfluorobutane sulfonate.

Other known PAGS also may be employed in the resists of the invention.Particularly for 193 nm imaging, generally preferred are PAGS that donot contain aromatic groups, such as the above-mentionedimidosulfonates, in order to provide enhanced transparency.

Other suitable photoacid generators for use in present photoresistsinclude for example: onium salts, for example, triphenylsulfoniumtrifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfoniumtrifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfoniumtrifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate,nitrobenzyl derivatives, for example, 2-nitrobenzyl p-toluenesulfonate,2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzylp-toluenesulfonate; sulfonic acid esters, for example,1,2,3-tris(methanesulfonyloxy)benzene,1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, forexample, bis(benzenesulfonyl)diazomethane,bis(p-toluenesulfonyl)diazomethane; glyoxime derivatives, for example,bis-O-(p-toluenensulfonyl)-α-dimethylglyoxime, andbis-O-(n-butanesulfonyl)-α-dimethylglyoxime; sulfonic acid esterderivatives of an N-hydroxyimide compound, for example,N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimidetrifluoromethanesulfonic acid ester; and halogen-containing triazinecompounds, for example,2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, and2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. One ormore of such PAGs can be used.

Photoresists of the invention also may contain other materials. Forexample, other optional additives include actinic and contrast dyes,anti-striation agents, plasticizers, speed enhancers, sensitizers, etc.Such optional additives typically will be present in minor concentrationin a photoresist composition except for fillers and dyes which may bepresent in relatively large concentrations such as, e.g., in amounts offrom 5 to 30 percent by weight of the total weight of a resist's drycomponents.

The resin binder component of resists of the invention are typicallyused in an amount sufficient to render an exposed coating layer of theresist developable such as with an aqueous alkaline solution. Moreparticularly, a resin binder will suitably comprise 50 to about 90weight percent of total solids of the resist. The photoactive componentshould be present in an amount sufficient to enable generation of alatent image in a coating layer of the resist. More specifically, thephotoactive component will suitably be present in an amount of fromabout 1 to 40 weight percent of total solids of a resist. Typically,lesser amounts of the photoactive component will be suitable forchemically amplified resists.

The photoresists of the invention are generally prepared following knownprocedures with the exception that a PAG of the invention is substitutedfor prior photoactive compounds used in the formulation of suchphotoresists. For example, a resist of the invention can be prepared asa coating composition by dissolving the components of the photoresist ina suitable solvent such as, e.g., a glycol ether such as 2-methoxyethylether (diglyme), ethylene glycol monomethyl ether, propylene glycolmonomethyl ether; lactates such as ethyl lactate or methyl lactate, withethyl lactate being preferred; propionates, particularly methylpropionate and ethyl propionate; a Cellosolve ester such as methylCellosolve acetate; an aromatic hydrocarbon such toluene or xylene; or aketone such as methylethyl ketone, cyclohexanone and 2-heptanone.Typically the solids content of the photoresist varies between 5 and 35percent by weight of the total weight of the photoresist composition.

The photoresists of the invention can be used in accordance with knownprocedures. Though the photoresists of the invention may be applied as adry film, they are preferably applied on a substrate as a liquid coatingcomposition, dried by heating to remove solvent preferably until thecoating layer is tack free, exposed through a photomask to activatingradiation, optionally post-exposure baked to create or enhancesolubility differences between exposed and nonexposed regions of theresist coating layer, and then developed preferably with an aqueousalkaline developer to form a relief image. The substrate on which aresist of the invention is applied and processed suitably can be anysubstrate used in processes involving photoresists such as amicroelectronic wafer. For example, the substrate can be a silicon,silicon dioxide or aluminum-aluminum oxide microelectronic wafer.Gallium arsenide, ceramic, quartz or copper substrates may also beemployed. Substrates used for liquid crystal display and other flatpanel display applications are also suitably employed, e.g. glasssubstrates, indium tin oxide coated substrates and the like. A liquidcoating resist composition may be applied by any standard means such asspinning, dipping or roller coating. The exposure energy should besufficient to effectively activate the photoactive component of theradiation sensitive system to produce a patterned image in the resistcoating layer. Suitable exposure energies typically range from about 1to 300 mJ/cm². As discussed above, preferred exposure wavelengthsinclude sub-200 nm such as 193 nm. Suitable post-exposure baketemperatures are from about 50° C. or greater, more specifically fromabout 50 to 140° C. For an acid-hardening negative-acting resist, apost-development bake may be employed if desired at temperatures of fromabout 100 to 150° C. for several minutes or longer to further cure therelief image formed upon development. After development and anypost-development cure, the substrate surface bared by development maythen be selectively processed, for example chemically etching or platingsubstrate areas bared of photoresist in accordance with procedures knownin the art. Suitable etchants include a hydrofluoric acid etchingsolution and a plasma gas etch such as an oxygen plasma etch.

The following non-limiting example is illustrative of the invention.

EXAMPLE 1 Synthesis of Nitrogen-Containing Compound (Compound 4 inScheme A)

The synthesis of the title compound (Compound 4 in Scheme A) isdescribed in the following Scheme A. The detailed synthetic proceduresfor each step are outlined below.

Part 1: Synthesis of Compound (2):

2-Amino-2-methyl-proane-1,3-diol (5 parts) and dodecanal (8.5 parts)were dissolved in 90/10 methylene chloride (20 parts), and (15 parts),separately. Dodecanal solution was added into2-amino-2-methyl-proane-1,3-diol solution with stirring at roomtemperature. The mixture was stirred at room temperature overnight andused in next step without purification.

Part 2: Synthesis of Compound (3):

The above mixture was cooled in an ice bath. Sodium borohydrid (3.8parts) was dissolved in 20 parts of 50/50 methylene chloride/methanoland added to the above mixture slowly. The resulting mixture was stirredat room temperature for 3 hr. Compound 3 was isolated by normal aqueousworkup followed by removal of solvent.

Part 3: Synthesis of Compound (4):

9.3 Parts of compound (3) and 9.7 parts of di-tert-butyl carbonate weredissolved in 40 parts of ethyl acetate, which was treated with 6.8 Partsof triethanol nitrogen-containing. The mixture was stirred for fourhours at room temperature. Compound 4 was isolated via silica gelchromatography using ethyl acetate as mobile phase.

EXAMPLE 2 Synthesis of Nitrogen-Containing Compound (Compound 6 inScheme B)

The synthesis of the title compound (Compound 6 in Scheme B) isdescribed in the following Scheme B. The detailed synthetic proceduresfor each step are outlined below.

Synthesis of Compound (6)

Dissolve 5 parts of 2-amino-2-hydroxymethyl-propane-1,3-diol in 70 partsof 1:1 methanol/tert-butanol mixed solvent. Dissolve 6.4 parts ofDi-tert-butyl carbonate in 50 parts of melting tert-butanol. AddDi-tert-butyl carbonate/tert-butanol solution into2-amino-2-hydroxymethyl-propane-1,3-diol/1:1 methanol/tert-butanolsolution slowly at room temperature and keep stirring overnight. Removesolvents. Re-crystallize by ethyl acetate.

EXAMPLE 3 Photoresist Preparation and Lithographic Processing

A photoresist of the invention is prepared by mixing the followingcomponents with amounts expressed as weight percent based on totalweight of the resist compositions:

Resist components Amount (wt. %) Resin binder 15 Photoacid generator 4Nitrogen-containing compound 0.5 Solvent 81

The resin binder is a terpolymer (2-methyl-2-adamantylmethacrylate/beta-hydroxy-gamma-butyrolactonemethacrylate/cyano-norbornyl methacrylate). The photoacid generator isthe compound t-butyl phenyl tetramethylene sulfoniumperfluorobutanesulfonate. The nitrogen-containing compound is theCompound 4 of Scheme A shown above in Example 1 and as prepared inExample 1 above. The solvent component is propylene glycol methyl etheracetate admixed with cyclohexanone and ethyl lactate. The resin, PAG andnitrogen-containing compound components are admixed in the solventcomponent.

The formulated resist composition is spin coated onto HMDS vapor primed4 inch silicon wafers and softbaked via a vacuum hotplate at 90° C. for60 seconds. The resist coating layer is exposed through a photomask at193 nm, and then the exposed coating layers are post-exposure baked at110° C. The coated wafers are then treated with 0.26N aqueoustetramethylammonium hydroxide solution to develop the imaged resistlayer.

EXAMPLE 4 Photoresist Preparation and Lithographic Processing

A photoresist of the invention is prepared by mixing the followingcomponents with amounts expressed as weight percent based on totalweight of the resist compositions:

Resist components Amount (wt. %) Resin binder 15 Photoacid generator 4Nitrogen-containing compound 0.5 Solvent 81

The resin binder is a terpolymer (2-methyl-2-adamantylmethacrylate/beta-hydroxy-gamma-butyrolactonemethacrylate/cyano-norbornyl methacrylate). The photoacid generator isthe compound t-butyl phenyl tetramethylene sulfoniumperfluorobutanesulfonate. The nitrogen-containing compound is thecompound Compound 6 of Scheme B shown above in Example 2 and as preparedin Example 2 above. The solvent component is propylene glycol methylether acetate admixed with cyclohexanone and ethyl lactate. The resin,PAG and nitrogen-containing compound components are admixed in thesolvent component.

The formulated resist composition is spin coated onto HMDS vapor primed4 inch silicon wafers and softbaked via a vacuum hotplate at 90° C. for60 seconds. The resist coating layer is exposed through a photomask at193 nm, and then the exposed coating layers are post-exposure baked at110° C. The coated wafers are then treated with 0.26N aqueoustetramethylammonium hydroxide solution to develop the imaged resistlayer.

EXAMPLE 5 Lithographic Results (Included Comparative Date)

A photoresist (Photoresist 1) corresponding to the formulation ofExample 3 was spincoated onto an organic bottom antireflective layerthat had been coated over a 300 mm silicon wafer. The Photoresist 1layer was softbaked to provide a dried layer thickness. An organic topcoat was then applied over the photoresist. The Photoresist 1 layer wasthen patternwise immersion exposed at 193 nm ASML 1900i; 1.3NA CQUAD 40°0.98/0/78σ XY Polarization). Following exposure, the imaged Photoresist1 layer was developed with 0.26N tetramethylammonium hydroxide aqueousdeveloper. Scanning electron micrographs (SEM's) of the resultingdeveloped Photoresist 1 is set forth at FIG. 1A of the drawings.

A comparative photoresist (Comparative Photoresist 1) corresponding tothe formulation of Example 1, except that the nitrogen-containingcompound contained a single hydroxyl group, was spincoated onto anorganic bottom antireflective layer that had been coated over a 300 mmsilicon wafer. The Comparative Photoresist 1 layer was softbaked toprovide a dried layer thickness. An organic top coat was then appliedover the photoresist. The Comparative Photoresist 1 layer was thenpatternwise immersion exposed at 193 nm ASML 1900i; 1.3NA CQUAD 40°0.98/0/78σ XY Polarization). Following exposure, the imaged ComparativePhotoresist 1 layer was developed with 0.26N tetramethylammoniumhydroxide aqueous developer. Scanning electron micrographs (SEM's) ofthe resulting developed Comparative Photoresist 1 is set forth at FIG.1B of the drawings. As can be seen from FIGS. 1A and 1 b, Photoresist 1provided a relief image with notably improved resolution (straighter andmore even printed lines) relative to Comparative Photoresist 1.

EXAMPLE 6 Lithographic Results (Included Comparative Date)

A photoresist (Photoresist 2) corresponding to the formulation ofExample 4 was spincoated onto an organic bottom antireflective layerthat had been coated over a 300 mm silicon wafer. The Photoresist 2layer was softbaked to provide a dried layer thickness. An organic topcoat was then applied over the photoresist. The Photoresist 2 layer wasthen patternwise immersion exposed at 193 nm ASML 1900i; 1.3NA CQUAD 40°0.98/0/78σ XY Polarization). Following exposure, the imaged Photoresist2 layer was developed with 0.26N tetramethylammonium hydroxide aqueousdeveloper. Scanning electron micrographs (SEM's) of the resultingdeveloped Photoresist 2 is set forth at FIG. 2A of the drawings.

A comparative photoresist (Comparative Photoresist 2) corresponding tothe formulation of Example 1, except that the nitrogen-containingcompound contained a single hydroxyl group, was spincoated onto anorganic bottom antireflective layer that had been coated over a 300 mmsilicon wafer. The Comparative Photoresist 2 layer was softbaked toprovide a dried layer thickness. An organic top coat was then appliedover the photoresist. The Comparative Photoresist 2 layer was thenpatternwise immersion exposed at 193 nm ASML 1900i; !0.3NA CQUAD 40°0.98/0/78σ XY Polarization). Following exposure, the imaged ComparativePhotoresist 1 layer was developed with 0.26N tetramethylammoniumhydroxide aqueous developer. Scanning electron micrographs (SEM's) ofthe resulting developed Comparative Photoresist 1 is set forth at FIG.2B of the drawings. As can be seen from FIGS. 2A and 2B, Photoresist 2provided a relief image with notably improved resolution (straighter andmore even printed lines) relative to Comparative Photoresist 2.

What is claimed is:
 1. A photoresist composition comprising: (a) one ormore resins; (b) one or more photoacid generator compounds; and (c) oneor more nitrogen-containing compounds that each comprise 1) two or morehydroxyl substituents and 2) one or more photoacid-labile ester groupsand/or photoacid-labile acetal groups, wherein the one or more of thenitrogen-containing compounds comprise one or more of the followingstructures:


2. A method for forming a photoresist relief image comprising: a)applying a coating layer of a photoresist composition of claim 1 on asubstrate; (b) exposing the photoresist coating layer to patternedactivating radiation and developing the exposed photoresist layer toprovide a relief image.
 3. A photoresist composition comprising: (a) oneor more resins; (b) one or more photoacid generator compounds; and (c)one more nitrogen-containing compounds that each comprise 1) two or morehydroxyl substituents and 2) one or more photoacid-labile ester groupsand/or photoacid-labile acetal groups, wherein one or more of thenitrogen-containing compounds correspond to the following Formula (IIB):

wherein in Formula (IIB) R¹ and R² are the same or different and atleast one of R¹ and R² is other than hydrogen, and together R¹ and R²comprise at least two hydroxyl groups, or R¹ and R² may be takentogether to form a ring where the ring (including substituents thereof)comprises at least 2 hydroxy groups; and R_(1′), R_(2′) and R_(3′) eachindependently represent an optionally substituted straight, branched orcyclic group of 1 to 30 carbon atoms.
 4. A photoresist compositioncomprising: (a) one or more resins; (b) one or more photoacid generatorcompounds; and (c) one more nitrogen-containing compounds represented byone of the following Formula (I):

wherein R¹ and R² are the same or different and at least one of R¹ andR² is other than hydrogen, and wherein R¹ comprises at least twohydroxyl groups, or R² comprises at least two hydroxyl groups, or R¹ andR² are taken together to form a ring where the ring (includingsubstituents thereof) comprises at least 2 hydroxy groups; and Xcomprises a photoacid-labile group.
 5. The photoresist composition ofclaim 4 wherein R¹ comprises at least two hydroxyl groups.
 6. Thephotoresist composition of claim 4 wherein R² comprises at least twohydroxyl groups.
 7. The photoresist composition of claim 4 wherein R¹ ishydrogen and R² is a non-hydrogen group that comprises at least twohydroxyl groups.
 8. The photoresist composition of claim 4 wherein R¹and R² are taken together to form a cyclic structure.
 9. The photoresistcomposition of claim 4 wherein one or more of the nitrogen-containingcompounds correspond to the following Formula (IIC):

wherein R₁, R₂ and R₃ each independently represent an optionallysubstituted straight, branched or cyclic group of 1 to 30 carbon; R₄represents hydrogen or a straight, branched or cyclic group of 1 to 30carbon; m1, m2 and m3 are each independently an integer of 0 to 30; n1,n2 and n3 are each independently an integer of 0 or 1; at least twoamong n1, n2 and n3 are
 1. 10. The photoresist composition of claim 4wherein one or more of the nitrogen-containing compounds correspond tothe following Formula (IID):

wherein R₁, R₂ and R₃ each independently represent a straight, branchedor cyclic group of 1 to 30 carbon; R₄ represents hydrogen or anoptionally substituted straight, branched or cyclic group of 1 to 30carbon; n is an integer of 1 to 30; and n is a positive integer e.g.from 1 to
 20. 11. A method for forming a photoresist relief imagecomprising: a) applying a coating layer of a photoresist composition ofclaim 4 on a substrate; b) exposing the photoresist coating layer topatterned activating radiation and developing the exposed photoresistlayer to provide a relief image.
 12. A method for forming a photoresistrelief image comprising: a) applying a coating layer of a photoresistcomposition of claim 5 on a substrate; b) exposing the photoresistcoating layer to patterned activating radiation and developing theexposed photoresist layer to provide a relief image.
 13. A method forforming a photoresist relief image comprising: a) applying a coatinglayer of a photoresist composition of claim 6 on a substrate; b)exposing the photoresist coating layer to patterned activating radiationand developing the exposed photoresist layer to provide a relief image.14. A method for forming a photoresist relief image comprising: a)applying a coating layer of a photoresist composition of claim 7 on asubstrate; b) exposing the photoresist coating layer to patternedactivating radiation and developing the exposed photoresist layer toprovide a relief image.
 15. A method for forming a photoresist reliefimage comprising: a) applying a coating layer of a photoresistcomposition of claim 8 on a substrate; b) exposing the photoresistcoating layer to patterned activating radiation and developing theexposed photoresist layer to provide a relief image.
 16. A method forforming a photoresist relief image comprising: a) applying a coatinglayer of a photoresist composition of claim 9 on a substrate; b)exposing the photoresist coating layer to patterned activating radiationand developing the exposed photoresist layer to provide a relief image.17. A method for forming a photoresist relief image comprising: a)applying a coating layer of a photoresist composition of claim 10 on asubstrate; b) exposing the photoresist coating layer to patternedactivating radiation and developing the exposed photoresist layer toprovide a relief image.
 18. A method for forming a photoresist reliefimage comprising: a) applying a coating layer of a photoresistcomposition of claim 3 on a substrate; (b) exposing the photoresistcoating layer to patterned activating radiation and developing theexposed photoresist layer to provide a relief image.